import React, { Component } from 'react';
import PropTypes from 'prop-types'
import {nanoid} from 'nanoid'
import './index.css'
class Header extends Component {
  //对接收的props进行类型、必要性的限制
  static propTypes = {
    addTodo:PropTypes.func.isRequired
  }
  handleKeyUp = (event)=>{
    // console.log(event.target.value);
    const {keyCode,target} = event
    if(keyCode !== 13) return
    if(target.value.trim() ===""){
      alert('输入不能为空');
      return;
    }
    const todoObj = {id:nanoid(),name:target.value,done:false}
    this.props.addTodo(todoObj)
    target.value = ''
  }
  render() {
    return (
      <div className="todo-header">
        <input type="text" onKeyUp={this.handleKeyUp} placeholder="请输入你的任务名称，按回车键确认"/>
      </div>
    );
  }
}

export default Header;